I have just begun researching one of my ancestral lines, and I have run into a roadblock. I have an ancestor who was born in Denmark sometime between 1838-1842 (birth year is derived from U.S. census records). The earliest location I have for him is Duluth, Minnesota in 1875. I cannot find him on any emigration/passenger lists on Ancestry.com. His name was William Jacobsen. That is all I know about him before his marriage to Ingibjorg Arnadottir in Duluth Minnesota in 1878.
Can anyone point me in the direction of an expert on Danish-U.S./Canadian emigration in the mid-1850s? If so, I would greatly appreciate it.